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MATH(3) FreeBSD Library Functions Manual MATH(3)
NAMEmath -- floating-point mathematical library
LIBRARY
Math Library (libm, -lm)
SYNOPSIS#include <math.h>
DESCRIPTION
These functions constitute the C math library.
LIST OF FUNCTIONS
Each of the following double functions has a float counterpart with an
`f' appended to the name and a longdouble counterpart with an `l'
appended. As an example, the float and longdouble counterparts of
doubleacos(doublex) are floatacosf(floatx) and longdoubleacosl(longdoublex), respectively.
AlgebraicFunctionsNameDescription
cbrt cube root
fma fused multiply-add
hypot Euclidean distance
sqrt square root
ClassificationFunctionsNameDescription
fpclassify classify a floating-point value
isfinite determine whether a value is finite
isinf determine whether a value is infinite
isnan determine whether a value is NaN
isnormal determine whether a value is normalized
ExponentManipulationFunctionsNameDescription
frexp extract exponent and mantissa
ilogb extract exponent
ldexp multiply by power of 2
scalbln adjust exponent
scalbn adjust exponent
Extremum-andSign-RelatedFunctionsNameDescription
copysign copy sign bit
fabs absolute value
fdim positive difference
fmax maximum function
fmin minimum function
signbit extract sign bit
ResidueandRoundingFunctionsNameDescription
ceil integer no less than
floor integer no greater than
fmod positive remainder
llrint round to integer in fixed-point format
llround round to nearest integer in fixed-point format
lrint round to integer in fixed-point format
lround round to nearest integer in fixed-point format
modf extract integer and fractional parts
nearbyint round to integer (silent)
nextafter next representable value
nexttoward next representable value
remainder remainder
remquo remainder with partial quotient
rint round to integer
round round to nearest integer
trunc integer no greater in magnitude than
The ceil(), floor(), llround(), lround(), round(), and trunc() functions
round in predetermined directions, whereas llrint(), lrint(), and rint()
round according to the current (dynamic) rounding mode. For more infor-
mation on controlling the dynamic rounding mode, see fenv(3) and
fesetround(3).
SilentOrderPredicatesNameDescription
isgreater greater than relation
isgreaterequal greater than or equal to relation
isless less than relation
islessequal less than or equal to relation
islessgreater less than or greater than relation
isunordered unordered relation
TranscendentalFunctionsNameDescription
acos inverse cosine
acosh inverse hyperbolic cosine
asin inverse sine
asinh inverse hyperbolic sine
atan inverse tangent
atanh inverse hyperbolic tangent
atan2 atan(y/x); complex argument
cos cosine
cosh hyperbolic cosine
erf error function
erfc complementary error function
exp exponential base e
exp2 exponential base 2
expm1 exp(x)-1
j0 Bessel function of the first kind of the order 0
j1 Bessel function of the first kind of the order 1
jn Bessel function of the first kind of the order n
lgamma log gamma function
log natural logarithm
log10 logarithm to base 10
log1p log(1+x)
pow exponential x**y
sin trigonometric function
sinh hyperbolic function
tan trigonometric function
tanh hyperbolic function
tgamma gamma function
y0 Bessel function of the second kind of the order 0
y1 Bessel function of the second kind of the order 1
yn Bessel function of the second kind of the order n
Unlike the algebraic functions listed earlier, the routines in this sec-
tion may not produce a result that is correctly rounded, so reproducible
results cannot be guaranteed across platforms. For most of these func-
tions, however, incorrect rounding occurs rarely, and then only in very-
close-to-halfway cases.
SEE ALSOfenv(3), ieee(3)HISTORY
A math library with many of the present functions appeared in Version 7
AT&T UNIX. The library was substantially rewritten for 4.3BSD to provide
better accuracy and speed on machines supporting either VAX or IEEE 754
floating-point. Most of this library was replaced with FDLIBM, developed
at Sun Microsystems, in FreeBSD 1.1.5. Additional routines, including
ones for float and longdouble values, were written for or imported into
subsequent versions of FreeBSD.
BUGS
The log2() and nan() functions are missing, and many functions are not
available in their longdouble variants.
Many of the routines to compute transcendental functions produce inaccu-
rate results in other than the default rounding mode.
On some architectures, trigonometric argument reduction is not performed
accurately, resulting in errors greater than 1 ulp for large arguments to
cos(), sin(), and tan().
FreeBSD 6.0 April 5, 2005 FreeBSD 6.0